Excavator



T. 1. FREDA.

EXCAVATOR.

APPLICATION man MAY 1, 1920.

Patented June 7,1921.

atroz Mug T. J. FREDA.

EXCAVATOR.

Y APPLICATION FHfED MAY l 1920. 1,380,79@ Patented June 7, 1921. I4 SHEETS-SHEET 2.

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T. J. FREDA.

EXCAVATOR.

APPLICATION FILED MAY 1| 1920. 1,380,790., Patented June 7, 1921.

14 SHEETS-SHEET 3.

A /7 g A s@ T. J. FREDA.

EXCAVATOR.

APPLICATION FILED MAY I. 1920.

l,380790 Patented June 7, 1921.

14 SHEETS-SHEET 4.

31a/verdon @EaP/w; J Has-,7A

T. J. FREDA.

vEXCAV/NOR.

APPLICATION man MAY 1. 1920.

'Lg'gg Patented 111116 7, 1921.

14 SHEETS-SHEET s.

gnvenfofp T. J. FREDA.

EXCAVATOR.

APPLICATION man MAY l, 1920.

1,380,790, Patented June 7, 1921.

14 SHEETS-SHEET 6| J. FREDA.

EXCAVATOR.

APPLICATION FILED MAY I, 1920.

1,38%799., PatentedJune 7, 192i.

i4 SHEETS-SHEET 7.

I: r -I /IIvE/vroR @50PM/ J 779524 S' BY ATTORNEY T. J. FREDA..

EXCAVATOR.

APPLICATION FILED MAY I. 1920.

1,380,799. Patented June 7, 1921.

I4 SHEETS-SHEET 8.

A TTOR/VE Y T. J. FREDA.

EXCAVATOR.

APPLICATION FILED MAY I| I920.

1,38639@ A Pand Jim@ 7, 1921.

14 SHEETS-SHEET 9- T. J. FREDA.

EXCAVATOR. y

APPLICATION FILI-:D MAY l, 1920.

1,880,790., PatentedJune 7,1921.,

I4 SHEETS-SHEET l0.

/NvE/vroR N THEO/DML J Fas-,7A

QM @69m TTORNE Y T. l. FREDA.

' EXCAVATOR.

APPLICATION FILED MAY 1, 1920.

LSSURQG., Patented June 7, 192i..

I4 SHEETS-SHEET H.

/N VEN TOR /EaF/f/L J. Kef-PA A TTORNE Y T. J. FREDA.

EXCAVATOR.

APPLICATION FILED MAY l. 1920.

Patented June 7, 1921.,

14 sHEETs-sHEET x2.

N VE N TOR 6 Z/EOPHM J FPL-fa I. J. FREDA.

EXCAVATOR.

APPLICATION FILED MAY I, |920.

1,880.790., mama June 7, 1921.

I4 SHEETS-SHEET I3.

BY @98M T. J. FREDA.

EXCAVATOR.

APPLlcAnoN `FILED MAY 1. |920.

1.938%?900 PatentedJune 7, 1921..

14 SHEETS-SHEET I4.

BY cx@ @MXUM A TTORNE Y f entre n or.

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Specification of Letters Patent. Patent-,Qd Jun@ 79 119213 application mee may 1, 1920. serial No. 378,057.

' To all whom t may concern Be it known that THEOPHIL J. FREDA, citizen of the United States, residin at Detroit, county of Wayne, State of 10h1- gan, have invented a certain new and useful Improvement; in Excavators, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference -being had to the accompanyin drawings, which form a part of this speci cation.

My inventionLrelates to excavators, particularly ditch d igging machinery. The object is to provide a machine composed of rotary cutting elements, connected together to form a train, being of successively 1ncreasing diameter from front to rear of such train and adapted Ito move forward through the earth as a unit excavating the ditch to size desired and provided with means for removing and carrying away such excavated earth.

In the drawings,- A

Figure 1 is a plan view, partly in section showing two units.

Fig. 1a is an elevation showing the means whereby one of the sta-tionary drums is connected with the truss work carried by one of the driveshaft tractors.

Fig. 1b is an elevation, partly broken away, showlng three vertical units.

Fig. 2 is a vertical section through one of the rotary cutting elements.

Fig. 3 is a cross-section on the line 3-3 of Fig. 2.

Fig. 4 is a cross-section on the line 4-4 of F'i 2. i

ig. 5 is a front elevation showing the machine in position and showing rthe overhead supporting bridge.

Fig. 6 is 'a diagrammatic view of the elevator and conveyer systems.

Fig. 7 is a fragmentary. elevation, partly in section, showing means for driving one of the conveyer belts.

Fig. 8 is an elevation, partly broken away, showing one of the lateral elevator chains and means for driving the same.

Fig. 9 is a plan, partly diagrammatic, showing the dumping chutes and main con ve er.

ig. 10 is a fragmentary elevation showing relative position of elevator scoops and chute.

Fig. 11 is a diagram vshowing dumping of earth from. scoops to chute.

F1 12 is an elevation showing screw borve ement at forward end of machine. 1g. 13 1s a fragmentary elevation show- 1ng stepped platform base and supporting tractors.

Flg. 14 is a plan of one of the supporting tractor devices. v

Fig. 15 is a side elevation taken on the line 15- 15 of Fig. 14. A

Fig. 16 is a section taken on the line'16-16 of ig. 14.

Fig. 17 1s a plan ofl one of the tractors which supports a main drive shaft and the I-beamsas supports for the drums.

Flg. 18 is a section taken on the line 18-18 of Fig. 17. I

Fig. 19' is a section section through a through the the belt reciprocally around the circumference of one of the stationary drums.

Fig. 24 is a modification showing diHerent means for clearinga path for the stationary drum.

In the drawings, 1 indicates centrally positioned base beams, here shown as I- beams, suitably supported on tractors 2, and carrying rotary cutting elements built up in vertical columns to ldesired height as shown in Fig. 1b. rlhese central base beams,

. which support separate cutting units are connected together as shown in Fig. 1b and Fig. 13, so connected together, they form a stepped platform base adapted to support the rotary cutters. l

Each central base beam 1, supports a stationary drum 3 formed with a iiange 3l and fashioned with an intervening web portion 3b. Disposed for rotation within this drum, suitably supported on roller bearings 3 is a rotary cutter, the operation of which is more clearly shown in Fig. 2.

This rotary cutter comprises a pair ofrings indicated as 4 and 4, lower and upper rings respectively, spaced from one another and held in such relationship by means of upright standards 5. These standards 5 `not only connect the rings together to form same to roll inwardly over the platform\ and down into the interior of the rotary cutting element,there to be picked up and carried away as hereinafter described. rfhe4 outward flare of these knives and the slope of the platform are more clearly shown 1n Fi 19 he upper ring 4FL is formed somewhat differently fromv the lower ring, as shown in Fig. 2, being formed with an overhang'ing flange spaced from 'the lower portion of said ring so as to provide a circumferential recess within which is received flange Sacar ried by the upper stationary drum 8. Sultable roller bearings are provided to pe'rmlt free rotation. These rings'4 and 4a are exteriorly geared so as to be driven by` chains 9, as shown in Fig. 1, which chains are driven from vertical drive shaft 10, which is provided wllth gears 10a so as to suitably drive said chains. These vertical drive shafts 10 are sup-l ported by separate tractor elements 11, as shown in Fig. 17, and are positioned one each between succeeding rotary cutting units as shown in Fig. 1 and Fig. 1*.` Each shaft is provided at the lower end thereof with a bevel gear 10b adapted to mesh with a bevel gear 12a carried by axle 12 which connects opposite members of said pair of tractors-11. The tractors are directly driven by means of a chain drive 13 off the axle 12, as shown. To form a support for said shaft 10, and further form a supporting bearing for the tractor axle, a stub standard 14 is supported upon vbase-plate 14a which is carried by central ll-beam 1 previously referred to. -This stuby standard is adapted to form a bearing support for said shaft 10 as shown in Fig. 17. A crossemember 15 supported from said axle and by'said shaft 10 is shown carrying uprights 16. These upri hts 16 are suitably braced from each -ot er by lattice work, not shown, in the drawing but adapted so' as to form askele-k ton supporting framework from which struts may be carried to the stationary drums vas shown in Fig. 1a.

` These main driving shafts l1() are driven from rear to front, as shown in Fig. 1 and Fig. 1b. The initial power impulse is sup- 'plied'from a power station or stations, not

shown in the drawing, but in well-known ineoeo fashion from any source of power supply. lt will be seen that each shaft 10 will drive` the rotary cutting element positioned ahead of it, and be in turn driven bythe rotarP cutting element positioned in its rear. t

`will be further observed that the tractor elements 11, which support the driving shafts 10 are on a level and of equal width with the diameter of the rotary cutting elements positioned forwardly' thereof; each cutting element l cuts to a certain width and depth and the tractor which supports' the shaft 10 following in the rear will follow that cut path. y

Chain 9 which drives the externall geared ring 4a from shaft 10, as previous y described, passes through passageways .provided through the drum as shown in Fig. 3, indicated at` 8b.

r1`hese rings 4y and 4a are also internally geared to mesh with gears 172L provided on shafts 17. rlhese shafts 17 are supported in the web portion of the drum with proper bearlngs not shown in the drawing, but in any suitable well known manner, and extend lbelow the level of the drums and I-beams tion to being partially supported by the rotar cutter itself is supported as shown in Flg. 1a by struts extending, from the trestle work built up on the tractor 11, and indicated as' to the uprights thereof as 16.

lDrum 8 is further adapted'to serve as` a lower supporting drum for a superimposed rotary cutter similar in all respects 'to the cutter just describedand driven in the same manner. Shafts 17, are adapted, asshown, to connect end to end so as to drive as'k one shaft from topto bottom.

lt will be seen that to form a further support'for this digging machinery and its. driving mechanism a bridge is provided, as shown in Fig. 5', indicated at 19, supported by tractors 20. These tractors should be driven from suitable sources of power supply in any convenient manner. Shafts 17 and shafts 10 extend upward to this overvhead framework and are partially supported thereby in suitable manner. This bridge work also serves as suitable means for supporting the conveyer systems hereinafter described. @ne of these bridge superstrucltures would preferably be provided for each rotary cutter tower. l.

meme@ 1n order tbtt a path may be prepared for the tractor w ich supports the lower ll-beam of the first unit, an excavating screw of known form is shown,- indicated as 21, Fig. l2, driven from gear 17b carried at the foot of the forwardly positioned shaft 17 'by means of a train of gears indicated as 22.

It will be seen that some means must be provided to convey the earth away which falls down through the interior of the spiral rotary cutter, and also means to excavate below the rotary cutter so as to form a pathway for the tractor which supports the center base beam of the succeeding rotary cutter' which, being at the same level as the tractor carried by the first unit, will be at a lower level than that to which the rotary cutter itself excavates. At this tractor supporting the second unit would normally be of greater dimension than the tractor supporting the first unit, the pathway excavated by the spiral screw would not be suiciently wide. There are therefore provided elevatorscoop systems, which not onlyelevate the earth as it falls inside the rotary. cutter from off the spiral platform, but also excavates the earth from the bottom of the ditch. y

The elevator conveyer system, s coo and otherwise, are shown in diagram inig. 6,: 23 indicates a main longitudinal overhead conveyer on which the earth elevated by the elevator scoop systems discharges and by which it is conveyed to the rear to be suitabl disposed of.

ach rotary unit is provided in the rear half thereof, with a laterally extending scoop elevator system indicated as 24, which passes over the main conveyer belt 23 and discharges therein. This chain of elevator scoops is driven as shown in Fig. 8 by means of. a train of gears 25 driven from ear 17b carried by shaft 17. This chain o scoops passes under the lower drum and the central base I-beam and is adapted to scoop up the earth from the bottom of the ditch as the machine advances. Depending brackets 25a are shown which support the gearing adapted to operate this chain scoop system. At the top of the machine, the train passes over gears carried by shaft 26, which shaft is suitably carried by the bridge work. This system of scoop elevators operates entirely within one rotary cutting tower.

In addition there is provided a longitudinally extending system of scoop elevators, two systems for the rst unit, one on each side, four in the second unit and in each succeeding unit, a pair on each side. 1n Fig. l in the iirst unit these are indicated as 27 and 27EL carrying scoops 27d.l Y

These systems are driven, as shown in Fig. 7, ofi of a shaft 17 by means of a train of gears '28 in the same manner that the reviously described system was driven. lach of these conveyer elevator scoop systems not only catches the falling earth as it rolls'o the s iral platform down through the center o the rotar cutter, but also scoops up the earth from t e bottom of the ditch.

The pair of systems 27 and 27 rises up through the first unit, extends to the rear passing over the gears 29 carried on shafts 29 which are supported in the bridge work in convenient manner, and down through the second rotary cutter, in the manner shown in Fig. 1b. These systems of elevator scoops likewise dump into the main conveyer belt 23,5 but for this purpose inclined dumping chutes are provided as shown in Figs. 9, 10 andll. The operation is shown most clearly in Fig. 11. rl.`hese inclined chutes are indicated as 30 and are suitably supported from the framework. It will be seen in Figs. 10 and 11 that the scoop 27d carried by the chain of scoops 27 will com- .mence to dum at approximately 4.5 degrees from the vertlcal and will complete this operation at or before the time it reaches the horizontal. The path of the falling earth is shown in Fig. 11. Thepath of the chain is then inwardly so that the scoop will -clear y the end of the chute. The earth'discharges from the chute into the main conveyer belt 23, asshown. The earth is conveyed by the main conveyer belt to some suitable dump in the rear and-discharged as desired. The rotary cutting units succeeding the first unit willbe seen to be provided with two parallel systems of longitudinally extending conveyers indicated as 27" and 27 in Fig. 1. The method of operation is identical with that just described.

To clear away the earth so as to provide a pathway for the stationary drum members, a reciprocating belt carrying cutter knives is provided adapted for operation around the circumference of these stationary drum members as shown in Fig. 20, which is a plan View of the lower drum member. The belt is indicated as 31, wound around spools 32 and 33 and provided with cutter knives 34, formed as shown to cut in either direction the belt reciprocates. The outer surface of the stationary drum is shown as provided with retaining flanges 31a. Spools 32v and 33 are in reality vertical shafts extending all the way up to the framework overhead and around which each of the reciprocating belts is wound so as to reverse them all at one operation. Of course separate reversing mechanism could be provided for each unit if desired.

A reversible clutch mechanism is housed -in casing 35, as shown in Fig. 23. 36 is a short shaft carrying a bevel gear 36a at the inner end adapted to mesh with a gear carried on a shaft 17. At the other end of the shaft 36 is a bevel gear 36" which meshes with gears 38a and 39a carried on sleeves 38 and 39 respectively, which sleeves are loosely1 mounted on shaft 37at the opposite ends et which are fixed bevel gears 37 and 37". 7llhe middle portion ot this shaft 37 is sfplined` s engagement with either of the sleeves 38 or 39 the shaft 37 will be driven therethrough.

rlhis reversing' operation is eected by means of a forked member 41 which embraces said collar in a oove provided therefor. rllhe opposite en of this forked member is provided with a roller 42 vvhlch rides in a groove in an elongated rotary member 43 which is mounted on shaft 43 and driven by chain 44 from a gear on shaft 10. lt will he seen that as this member 43 rotates it will reciprocate the collar 4&0 longitudinally on the shaft 3 7 bringing it into engagement with first one sleeve and then the other so as to drive irst one spool and then the other, thus reciprocating the band 31 and the cutters 34: will cut a pathfor the stationar drum. p

A mo ication is 'shown in Fig. 24 in which an endless chain 45 carrying cutting elements is mounted to rotate about the stationary drum 3. The web portion of the drum would have to be cut away to permit this chain to drive through and a multiplicity of these elements would have to be provided around the circumference of the drum. They' could drive independently in any convenient mannern llt is apparent that spiral platforms 6, but one ci? which is shown per cutter in the drawin s, may be provided in number desired. gFor example, three might be provided 'or the foremost cutting elements, and a greater number in the lar er cutting elements. 7ll`his would not on y increase the strength of the cutter itself but would increase the cutting capacity.

lt is furthermore apparent that instead of providing excavating units succeeding the foremost unit of greater diameters than such irst unit, two units might be provided, one

on each side of the median line and extending laterally equally beyond the zone excavated by the previous unit. These two units being of smaller diameter than the one large unit they supplant, would p ermit of lighter construction and be more adaptable in use. v l claim: y 1. llna ditch digging machine, a series of vertical, cylindrical, rotary excavators positioned one in the rear of the other to form a train, separate successive excavators being of increasing diameters from front to rear of said train, means connecting the same together so the unit, means or propelling the same forward means for rotating said excavators.

2. ln an excavator, a series of rotar cutters positioned in the rear of one anot er to will move 'forward -as onel form 'a train, separate cutters being or successively increasing diameters :trom the trent to the rearof said train, meansior supporting said cutters so they will move Jforward as one unit, means for rotating said cutters.

3. lln a ditch digging machine, a series of vertically disposed rotary cutter elements positioned one in rear of the other to form a train,v separate cutter elements bein of successively increasing diameters trom ront torear of said train and separate cutter elements likewise su ported at successively higher levels from ront to' rear of the train, means for supporting said cutter elements so that they may be moved forward as one unit, means for rotating said cutter elements. l

d. In a ditch digging machine, a series ot rotary cylindrical lcutter elements positioned l in the rear of one another to form a train supported at varyin levels, increasing from front to rear of sai train, each rotary cutter element comprising a cylindrical vertically positioned rotary cutter provided with a spiral platformcarrying a series of outwardly projectin knives adapted to cut away the earth urin the rotation of the cutter, means' for rotating the cutter.

5. ln a ditch digging machine, a series of p cylindrical cutter e ements mounted .for rotation positioned'one in the rear of the other to form a train, supporting means orsaid elements so they may advance as one unit, separate cutting elements being of varying diameters increasing :tromfront to rear of said train, each separate cutter element comprising a spiral platform ledge provided with a seriesot outwardly projecting lmives adapted to cutaway Athe earth during the rotation of such cutter and so' formed as to guide the earth cut away toward the interior i of the spiral platform, means for rotating said cutters;

6. lln a ditch digging machine, a base adapted for forward movement 'comprising a series ot platforms stepped from higher to lower levels from rear to front, a series of cylindrical rotary cutters positioned one on each platform for rotation,.said cutters being of varying diameters decreasing from higher tolower platforms, means for rotating said cutters, means for impelling the machine forwardly.

7 lln a ditch digging machine, a series of cylindrical cutter elements positioned one in t e rear .of the othervto form a train, supported so that they may move forward `as one unit, separate' cutter elements being of varying diameters increasing froml front to rear and supported at varying levels increasing in height from front to rear, separate cutter elementscomprising a spiral platform ledge supported between opposed end pieces,A said vspiral platform sloping toward the center ot the cylindrical cutter element, a

rae

aecomo series of scoops carried b saidplatform projecting outwardl there rom adapted to cut away the earth uring the rotation of such cutter element.

8. 1n a ditch digging machine, a series of cylindrical vertically disposed cutter elements positioned in the rear of one another and supported at varying levels increasing in height from front to rear so that they may be moved" forward as one unit in the form of a train, separate cutter elements he-` ing of varying diameters increasing from front to rear of the train, each cutter element comprising opposite end rings mounted so as to permit rotation of said cutter element about its vertical axis and a spiral platform ledge intervening said end rings,

vsaid platform ledge being provided with a lcutter elements positioned one on each 'of said platforms, said cutter elements being of varying diameters increasing from front to rear of said base, means for rotating each of said rotary cutter elements, each of said rotary cutter elements adapted for the superimposition of a similar rotary cutter element, a main conveyer comprising an endless belt exten-ding from front to rear of said train positioned above said rotary cutter elements, endless chains carrying elevator scoops adapted to rise upwardly through each of said rotary cutter elements and adapted to dump into the main conveyer and to pass down through the rotary cutter element positioned immediatel in the rear, the scoops of said elevator c ain adapted to scrape up earth from the bottom of the ditch.

10. 1n a ditch digging machine, a series of rotary cutter elements positioned one in the rear of the other to form a train, separate cutter elements being of varying diameters increasing successively from front to rear of said train and supported at varying levels increasing successively in height from front to rear, a central tractor support under each of said cutter elements, each of.

said cutter elements comprising opposed en-d pieces carrying between them a spiral circumferential platform ledge provided with -,projecting scoops ada ted to cut away the earth during the rotation of the cutter, main drive shafts positioned between separate cutter elements, means lfor driving each of said cutters from the drive shaft positioned in the vrear thereof, an excavating element 'positioned forwardly of the tractor `supporting the foremost rotary cutter element, an endless. belt carryin elevator scoops adapted to operate upwar y one on each side through said rotary cutter elements and adaptedl to scra e the earth from the bottom of the ditc on each side of the tractor under the rotary cutter through which it operates to a level with said tractor, means for driving said endless belts.

p 11. lin a device of the class described, a series of rotary cutter elements positioned one 1n the rear of the other to form a train of cutter elements of successively increasing diameters from front to rear and posiltioned at successively higher levels from front to rear `of said train, tractor supports for each of such'rotary cutters, such tractor supports connected together so that they will move forwardly as one unit, main drive shafts positioned between each of such rotary cutter elements, each of said cutter lelements comprising externally and internally geared opposed end rings carrying an intervening circumferential spiral platform ledge provided with projecting upstanding cutter scoops adapted to cut away the earth during the rotation of the spiral cutter, a drive chain meshing with the external gear on each of said end rings adapted to be driven from the main drive shaft positioned inthe rear thereof, vertical yshafts positioned in teriorly of said rotary cutters provided with gears meshing with the internally geared end rings so as to drive said shafts, such internally positioned shafts provided with gears adapted to drive a. train of gears adapted to drive endless chain elevator and conveyer scoop systems endless chains carrying elevator scoops adapted to operate upwardly through each of said rotary cutter .elements to carry away the earth falling therethrough and adapted to scrape up earth from the bottom of the ditch, means positioned forwardly ofthe tractor support for the foremost cutter element to clear away the earth ahead of such tractor element. l

12. ln a ditch digging machine, a series of rotary cutter elements positioned one in the rear of theother to forma train of cutter elements of successively increasing diameters from front to rear of said train, tractor supports for each of said cutter elements, a stationary drum carried by said tractor support in which the rotary cutter is mounted for rotation, a second stationary drum properly supported positioned so that the opposite end of said cutter element opcrates therein, means for driving said rotary cutters, said up'per drum adapted to receive a second similar rotary cutter element for superimposition over said first rotary cutter element, nreciprocating cutter bands adapted to 'operate around the circumference of said stationary drums.

13. lin a ditch dlggmg machine, a series of rotary cutter elements positioned one 1n the rear of the other to formi a train of cutter elements, such rotary cutters being of varying diameters inceasin from front to rear of such train and positioned at a yhigher level from front to rear,y tractor supports for each of 'such rotary cutters, endless chains of elevator scoops operating upwardly through said rotary cutters to carry away the earth falling therethrough, Such elevator scoops connected in chain extending downwardly below the bottom of the cutter elements so as to scrape up earth from the bottom of the ditch on each side of the tractor support for said rotary cutter, a rotary screwcutter positioned forwardly of the first tractor element to clear away the earth Jforwardly thereof.

1t. lin a ditch digging machine, a platform base properly supported upon a tractor element for movement, a stationary drum carried thereby, a rotary cylindrical cutter element positioned within said stationary drum for rotation, said rotary cutter' comprisin end rings externally and internally geare and a4 spiral platform intervening the same provided with outwardly projecting cutter scoops adapted to cut away the earth during the rotation of thel cutter, driven chains adapted to mesh with the external gearing of said end rings driving said cutter elements, vertically disposed shafts positioned internally of said cutter elements adapted to mesh with the internally geared circumference of the end rings so as to be driven thereby, a train of gears carried at the lower extremity of said internally positioned shafts provided with supporting brackets extending from the platform base said train of gears adaptedto be driven from the vertically disposed shafts and adapted in turn to drive the supporting tractor elements which support the platform base.

15. lin a ditch digging machine, a stepped platform base stepped from higher to lower levels from rear' to front provided with proper tractor supporting elements, a stationary drum carried on each stepped platform, a vertically disposed cylindrical rotary cutter comprising externally and internally geared end rings carrying intervening spiral platform provided with outwardly projecting scoops disposed within said drum for rotation, vertical drive shafts positioned between separate successive rotary cutters,

'drive chains driven thereby meshing with the external gearing on the end rings of the rotary cutters so as lto drive the same, vertical shafts positioned internally of the romeedraatary cutters ada ted to mesh with the internal gearing ci) the end rings so as to be driven thereby, endless chains of elevator scoops adapted to operate upwardly through` said rotary 'cutter elements to carry up t e earth falling therethrough, means carried by said vertical shafts positioned internally of the rotary cutters adapted to drive a train of gears to'operate said endless chains, one of said endless chains of elevator scoops adapted to operate on each side of the tractor support for `the rotary cutter to scrape away the earth below the rotary cutter element and alongside the tractor, an overhead conveyer belt into which the elevator scoops are adapted to dump.

16. In a ditch dlgging machine, a plul rality of earth cutting units operatively connected to progressively advance in unlson, said units each being movable on a vertical axis and'relatively located to remove the earth in successive increments located beyond the lateral bounds ofthe zone removed in the previous increment, whereby the progressive advance of the apparatus will produce an excavation of a wldth corresponding to the distance between the lateral bounds of the last removed increments.

17'. in a ditch digging machine, a plurality of earth cutting instrumentalities of increased diameter operatively connected to progressively advance in unison, said instrumentalities each being movable on a vertical axis and relatively located to remove the earth in a succession of increments located beyond the lateral bounds of the zone removed in the previous increment, whereby the progressive advance of the apparatus will produce an excavation of a width corresponding'to the distance between the lat-- eral bounds of the last removed increments.

18. ln excavating apparatus, a plurality of earth cutting instrumentalities operatively connected to progressively advance in unison, each of said instrumentalities including a plurality of cutting elements located in a spiral succession with the axis of the spiral corresponding to the axis of the instrumentality, said instrumentalities each being movable on a vertical axis and relatively located to remove the earth in a succession of increments with successive increments located beyond the lateralbounds of the zone removed in the previous increment, whereby the progressive advance of the apparatus will produce an excavation of a width corresponding to the distance between the lateral bounds of the last removed increments.

19. lin excavating apparatus, a plurality of earth-cutting instrumentalities operatively connected to progressively advance in unison, said instrumentalities each being movable on a vertical axis and relatively located 

